Bug 224753

Summary:

GraphViewer overwrites edge label on bidirectional graphs

Product:

[Tools] GEF

Reporter:

Erkki Lindpere <villane>

Component:

GEF-Legacy Zest

Assignee:

gef-inbox <gef-inbox>

Status:

NEW ---

QA Contact:

Severity:

normal

Priority:

CC:

irbull, oliver.oo.schaefer, tim.baumgartner

Version:

unspecified

Flags:

irbull: galileo+

Target Milestone:

---

Hardware:

OS:

Windows XP

Whiteboard:

Attachments:

Description	Flags
Edge exists in both directions	none
GraphViz rendering without labels	none
GraphViz rendering with labels for the bidirectional connection	none

Description Erkki Lindpere

2008-03-28 19:55:05 EDT

When GraphViewer is drawing directed connections and a connection exists in both directions, then the labels of the two connections will (may) overlap.
This was with SpringLayout, and the viewer was created like this:

viewer = new GraphViewer(parent, SWT.NONE);
viewer.setContentProvider(new ViewContentProvider());
viewer.setLabelProvider(new ViewLabelProvider());
viewer.setLayoutAlgorithm(new SpringLayoutAlgorithm(LayoutStyles.NONE));
viewer.setConnectionStyle(ZestStyles.CONNECTIONS_DIRECTED);
viewer.setNodeStyle(ZestStyles.NODES_NO_LAYOUT_RESIZE);

Comment 1 Erkki Lindpere

2008-03-28 20:00:35 EDT

Created attachment 94085 [details]
Edge exists in both directions

This screenshot shows the labels of edges f -> n and n -> f overlapping. The labels should be DirEdge(f,n) and DirEdge(n,f) respectively.

Comment 2 Ian Bull

2008-03-28 20:07:43 EDT

I have been experimenting with an API to set the location of the label on a line (from 0..100).  This way you could set the labels to be 75% of the way across the line (so the labels would appear close to the target nodes).  Do you think this would help you?

Comment 3 Erkki Lindpere

2008-03-29 06:09:13 EDT

Created attachment 94096 [details]
GraphViz rendering without labels

Comment 4 Erkki Lindpere

2008-03-29 06:09:49 EDT

Created attachment 94097 [details]
GraphViz rendering with labels for the bidirectional connection

Comment 5 Erkki Lindpere

2008-03-29 06:10:05 EDT

Yes, I think that would help. Also I think it would be good if bidirectional edges were a little apart from each other or you could create a control point and drag it manually. But maybe that would make the GraphViewer more complex than necessary? I'm not familiar with GEF -- perhaps more complex things should be done with other GEF components? I don't have a big need for this feature, I was just experimenting with Zest and found this issue.

Anyway, I attached two screenshots of the same graph rendered with GraphViz, one where the bidirectional relation has labels and one where it doesn't.

Comment 6 Oliver Schäfer

2009-02-04 02:24:56 EST

(In reply to comment #5)
> Also I think it would be good if bidirectional edges were a little apart from each other ...

This would be a very helpful feature.

Comment 7 Tim Baumgartner

2010-06-14 07:05:53 EDT

(In reply to comment #5)
> Also I think it would be good if bidirectional edges were a little apart from each other...

I would like this, too. The same applies if one has multiple edges between two nodes (e.g. when implementing IGraphEntityRelationshipContentProvider) regardless of their direction.

Comment 8 Alexander Nyßen

2015-01-22 02:44:33 EST

Re-assigning back to inbox, as Ian is no longer active committer.